In a 1959 lecture to the American Physical Society entitled “There is a lot of floor space,” Richard Feynman argued that there is tremendous opportunity to work in the world of molecules and atoms. He dreamed of ultra-small computers, cars that run under a microscope, and medical machines that work inside our bodies.
These dreams are now coming true. In 2017 we had the first World Nanocar Race in Toulouse, France. Six teams from around the world manipulated cars in the nanometer range in order to drive them under a scanning tunneling microscope on a metal surface. A nanocar is 2 billion times smaller than an ordinary car, which is the size difference between a grain of rice and the earth. Feynman only envisioned cars that were 4,000 times smaller than normal. However, some of the nanocars resembled cars, and none were powered by their own engines. There is still a lot of room for improvement.
The next step in nanotechnology is to develop nanoscale objects into functional materials. For this we need nano-architecture – a concept that Masakazu Aono proposed at an international conference in Tsukuba, Japan, in 2000. The term nanoarchitecture refers to the discipline (‘nics’) of architecture in the nano range. The aim is to design materials with precise structures from nanoscale units such as atoms, molecules and nanomaterials that offer a high level of performance. It is a nanoscale version of building construction or mechanical engineering.
Contributions from many scientific disciplines are required for this great challenge
Several research fields have developed the first forms of bottom-up architecture through which the self-organization of component molecules creates functional materials. The formation of structures through the self-organization of molecules and specific molecular recognition processes is currently a hot topic in supramolecular chemistry. In biochemistry, DNA origami technology enables the creation of well-designed structures through complementary base-pairing sequence-defined strands of DNA. These approaches are based on simple molecular interactions between limited components. In contrast to these traditional approaches, nanoarchitecture aims to design material structures universally, including more complicated (often asymmetrical and hierarchical) motifs made up of multiple components that go beyond known self-organization and related strategies.
This major challenge requires contributions from many scientific disciplines such as nanotechnology, supramolecular chemistry, materials science and biotechnology. Linking techniques between different sciences will be key. Atomic and molecular manipulation, organic chemical reactions, self-organization and self-organization, nano- and microfabrication, material processes, and bio-related techniques are just a few of the tools available – and they are already beginning to be combined.
For example, site-specific chemical reactions have been achieved through molecular manipulation through nanotechnological processes, using a nanoscale tip to position a molecule in a desirable position for a reaction to take place. The hierarchical arrangement of biomolecular motors with other materials such as composite polymer layers has led to the successful production of energy parts from a proton gradient. The regulation of atom-assembling structures in a tiny gap between electrodes has resulted in brain-like device outputs such as memorization, forgetting, and learning. The functioning of these atomic devices has even been investigated in experiments in space. Due to their high resistance to space radiation, the devices may prove useful in future alien missions.
Nano-architecture can also learn a lot from living things. A cell is practically a functioning factory. In living cells, unit molecules spontaneously form highly functional systems with complex hierarchical organizations made up of many different types of components. These molecules have their own tasks and roles and work together under nanoscale uncertainties such as thermal fluctuations. In addition to the sum of the individual interactions, effects and interactions play together harmoniously in order to obtain sophisticated functions. These biological systems are the ultimate models for products of nanoarchitecture, which is evident in the challenges of organizing nanomaterials for artificial photosynthesis.
Nano-architecture can be seen as a strategy for everything in materials science
Nanoarchitectonics is not entirely new. However, by defining it as a new concept and expressing our interest in it, it will be easier for us to acquire the resources and expertise we need to use it to take the next step. Just look at the nanotechnology initiative launched in the United States in 2000, which has greatly boosted nanoscience research activities around the world. The projects funded by the initiative opened the way to understanding nanoworlds. Thanks to nano-architecture, we can now create useful materials from these nano-worlds.
I believe that nano-architecture can be seen as a strategy for everything in materials science, similar to the theory of everything in physics. While the theory of anything could explain all basic science, nano-architecture opens the way to produce anything we could want. It is a necessary historical step for developments in materials science and chemistry. It is high time to combine all independently developed approaches to material design and manufacturing into a single concept of nanoarchitecture. We learned a lot about nano; Now is the time to make goods with nano.